Communication environment switchover

ABSTRACT

Communication environment switchover may be provided. A received signal strength level may be determined corresponding to a signal sent from a first device and received at a second device. The received signal strength level may be measured at the second device. In addition, the first device may be re-provisioned. For example, the first device may be re-provisioned to communicate in a second environment if the first device is provisioned to communicate in a first environment and if the received signal strength level is greater than a first threshold value. Furthermore, the first device to be re-provisioned to communicate in the first environment if the first device is provisioned to communicate in the second environment and if the received signal strength level is less than a second threshold value. The second threshold value may be less than the first threshold value.

RELATED APPLICATIONS

This application is a continuation-in-part (CIP) of U.S. applicationSer. No. 10/614,737, filed Jul. 7, 2003, which is incorporated herein byreference. Furthermore, under provisions of 35 U.S.C. §119(e),Applicants claim the benefit of U.S. provisional application No.60/794,925, filed Apr. 26, 2006, and U.S. provisional application No.60/798,824, filed May 9, 2006, both of which are incorporated herein byreference.

BACKGROUND

A dual mode handset (DMH) is the combination of a wireless fidelitysession initiation protocol (WiFi SIP) cordless telephone and a cellulartelephone. The DMH is capable of operating in an IEEE 802.11 standardenvironment, such as 802.11 b/g, over an unlicensed spectrum inside ahome or business and in a cellular environment (such as GSM or CDMA)over licensed spectrum. The DMH can be designed such that it can “roam”between WiFi and cellular environments. Moreover, the DHM can support anactive call handover when roaming between environments when there isoverlap between the WiFi coverage and the cellular coverage. This oftencauses problems because the conventional roaming strategy many timescauses active calls to be dropped when roaming between environments. Forexample, when switching to WiFi during roaming, while a WiFi signal maybe present, it may be too weak to support quality communications.

SUMMARY

Consistent with embodiments of the present invention, communicationenvironment switchover may be provided. A received signal strength levelmay be determined corresponding to a signal sent from a first device andreceived at a second device. The received signal strength level may bemeasured at the second device. In addition, the first device may bere-provisioned. For example, the first device may be re-provisioned tocommunicate in a second environment if the first device is provisionedto communicate in a first environment and if the received signalstrength level is greater than a first threshold value. Furthermore, thefirst device to be re-provisioned to communicate in the firstenvironment if the first device is provisioned to communicate in thesecond environment and if the received signal strength level is lessthan a second threshold value. The second threshold value may be lessthan the first threshold value.

It is to be understood that both the foregoing general description andthe following detailed description are examples and explanatory only,and should not be considered to restrict the invention's scope, asdescribed and claimed. Further, features and/or variations may beprovided in addition to those set forth herein. For example, embodimentsof the invention may be directed to various feature combinations andsub-combinations described in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate various embodiments of the presentinvention. In the drawings:

FIG. 1 shows a system for providing communication environmentswitchover;

FIG. 2 shows a structure from the system for providing communicationenvironment switchover shown in FIG. 1;

FIG. 3 shows a processor; and

FIG. 4 shows a flow chart of an exemplary method for providingcommunication environment switchover.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.Wherever possible, the same reference numbers are used in the drawingsand the following description to refer to the same or similar elements.While embodiments of the invention may be described, modifications,adaptations, and other implementations are possible. For example,substitutions, additions, or modifications may be made to the elementsillustrated in the drawings, and the methods described herein may bemodified by substituting, reordering, or adding stages to the disclosedmethods. Accordingly, the following detailed description does not limitthe invention. Instead, the proper scope of the invention is defined bythe appended claims.

Communication environment switchover may be provided. FIG. 1 shows asystem for providing communication environment switchover 100.Consistent with embodiments of the present invention, a first device 105is capable of operating in a first environment 110 and within a secondenvironment 115. First environment 110 may comprise a wireless networksuch as a cellular environment (e.g., GSM, TDMA, CDMA, CDMA 2000, UTMS,and EDGE) over a licensed (i.e., regulated) spectrum. Second environment115 may comprise a packetized data network comprising, for example, aWiFi/voice-over-internet protocol (VoIP) network. Second environment 115may utilize the IEEE 802.11 standard (e.g., 802.11b/g) over anunlicensed (i.e., unregulated) spectrum inside or outside a structure120 (e.g., a home or business). First environment 110 may comprise alicensed (i.e., regulated) environment that may utilize regulatedwireless communications frequencies comprising frequencies assigned to aservice provider. Second environment 115 may comprise an unlicensed(i.e., unregulated) wireless environment configured to provide wirelessservice over at least one frequency not assigned to a service provider.The service provider may comprise any enterprise that providescommunications services.

First device 105 may comprise a DMH. As stated above, DMH is thecombination of a WiFi SIP cordless phone and a cellular phone. It iscapable of operating, for example, in an 802.11 environment, such as802.11b/g, over unlicensed spectrum inside a home or business and in acellular environment, such as GSM or CDMA, over licensed spectrum.Supported by 3GPP IP Multimedia Subsystem (IMS) infrastructure, a DMH,for example, can roam between the second environment 115 (e.g.,WiFiNoIP) and the first environment 110 (e.g., GSM cellular).Furthermore, DMH can support “in-call handover” of an active telephonecall when roaming, for example, from a WiFiNoIP environment to a GSMcellular environment or from a GSM cellular environment to a WiFi/VoIPenvironment. An in-call handover can occur, for example, if there isoverlap between the WiFi coverage and the GSM cellular coverage.Consequently, consistent with an embodiment of the invention, a processis provided for effectively and reliably triggering roaming, forexample, from the GSM cellular environment to a WiFiNoIP environment andfor triggering in-call handovers between WiFiNoIP and GSM environments.While the aforementioned is described in terms of roaming between aWiFiNoIP environment to a GSM cellular environment, these environmentsare examples and embodiments of the invention may roam between any twoor more environments.

As shown in FIG. 1, first environment 110 comprises a GSM/UMTS system.In this example, first environment 110 comprises, for example, a basestation controller (BSC) 125 and base transceiver stations (BTSs) 130and 135. BSC 125 controls BTS 130 and may control a plurality of otherbase transceiver stations (e.g., BTS 135) in addition to BTS 130. BTS130 may comprise radio transmission and reception equipment located atan antenna site. Associated with first environment 110, atranscoder/rate adaption unit (TRAU) (not shown) may perform speechencoding and speech decoding and rate adaptation for transmitting data.As a subpart of BTS 130, the TRAU may be located away from BTS 130, forexample, at a remote mobile switching center. When the TRAU is locatedin this way, the low transmission rate of speech code channels allowsmore compressed transmission between BTS 130 and the TRAU.

Furthermore, first environment 110 includes a mobile switching center(MSC) 140, a home location register (HLR) 145, and a gateway mobileswitching center (GMSC) 150. GMSC 150 manages the communication betweensubscribers using first environment 110 and other telecommunicationsusers, for example, those using publicly switched telephone network(PSTN) 152. PSTN 152 may comprise, for example, the worldwide voicetelephone network.

MSC 140 coordinates call set-up to and from subscribers such as a userusing DMH 105. MSC 140 may control several base station controllers suchas, and similar to BSC 125. GMSC 150 is used to interface with externalnetworks for communication with users outside of the wireless system,such users on PSTN 152.

HLR 145 may comprise a stand-alone computer without switchingcapabilities, a database that contains subscriber information, andinformation related to the subscriber's current location, but not theactual location of the subscriber. An authentication center (AUC)portion (not shown) of HLR 145 manages the security data for subscriberauthentication. Another sub-division of HLR 145 may include an equipmentidentity register (EIR) (not shown) that may store data relating tomobile equipment.

First environment 110 may also include a visitor location register (VLR)(not shown). The VLR links to one or more mobile switching centerlocated on other systems, temporarily storing subscription data ofsubscribers currently served by MSC 140. The VLR holds more detaileddata than HLR 145.

GMSC 150 is utilized to interface with PSTN 152. In order to set up arequested call, the call is initially routed to GMSC 150, that finds thecorrect home location register by knowing the director number of thesubscriber. GMSC 150 has an interface with an external network, such asPSTN 152, for gatewaying communications.

First environment 110 and second environment 115 are connected using asignal system 7 (SS7) network 154 in an ISDN user part (ISUP) protocol.SS7 is a global standard for telecommunications defined by theTelecommunication Standardization Sector of the InternationalTelecommunication Union. The SS7 standard defines the procedures andprotocol by which network elements in a public switched telephonenetwork exchange information over a digital signaling network to effectwireless and wireline call setup, routing, and control. ISUP defines theprotocol and procedures used to set-up, manage, and release trunkcircuits that carry voice and data calls over a public switchedtelephone network. ISUP is used for both ISDN and non-ISDN calls. Callsthat originate and terminate at the same switch do not use ISUPsignaling.

First environment 110 may also enable general packet radio service(GPRS). GPRS is an enhancement to the GSM mobile communications systemthat supports data packets. GPRS enables continuous flows of IP datapackets over the system for such applications as Web browsing and filetransfer. In order to implement GPRS, first environment 110 may use RNC156 and GPRS service node (xGSN) 158 to connect DMH to an IP WAN 160(e.g., the Internet).

Second environment 115 includes 3GPP IP Multimedia System (IMS)infrastructure 162, a telephony feature server 164, a handover featureserver 165, a multimedia gateway (MGW) 166, an HSS 168, a messagingserver 170, IP WAN 160, and a broadband access network 172. IMS 162comprises a number of different servers, at least one of which causesactive calls to be handed between first environment 110 and secondenvironment 115. To facilitate DMH 1053's roaming between firstenvironment 110 and second environment 115, IMS 162 may set-up athree-party call between DMH 105 on both environments. Once thethree-party call is established, IMS 162 may drop the leg of thethree-party call corresponding to the environment from which DMH 105 isroaming.

Telephony feature server 164 provides users in second environment 115various calling feature, such as call waiting, caller ID, and callforwarding to name a few. Messaging server 170 provides users in secondenvironment 115 with voice message features. MGW 166 is used to connectPSTN 152 with IP WAN 160, that may comprise, for example the Internet.Broadband access network 172 may comprise a network operated by aservice provider used to provide access to IP WAN 160 from structure120.

FIG. 2 shows structure 120 in more detail. For example, the user may beusing DMH 105. As the user get closer to the wireless access point 205,a received signal strength level from DMH 105′, as measured at wirelessaccess point 205, may be greater than or equal to the first thresholdvalue as illustrated by a first circle 210. In this case, as describedin more detail below, DMH 105′ switches from operating in firstenvironment 110 to operating in second environment 115. Furthermore, ifthe user gets farther from wireless access point 205, the receivedsignal strength level from DMH 105 as measured at wireless access point205 may be less than or equal to the second threshold value asillustrated by a second circle 215. In this case, as described in moredetail below, DMH 105 switches from operating in first environment 115to operating in second environment 110. In this way, DMH 105 may roambetween environments as described above. When DMH 105″ is between firstcircle 210 and second circle 215, DMH 105″ remains operating in theenvironment it is currently provisioned to operate. For example, if DMH105″ passed from outside second circle 215 to the area between firstcircle 210 and second circle 215, DHM 105″ remains provisioned tooperate in first environment 110. If, however, DMH 105″ passed frominside first circle 210 to the area between first circle 210 and secondcircle 215, DHM 105″ remains provisioned to operate in secondenvironment 115. While FIG. 2 shows first circle 210 and second circle215 as being symmetrical, the boundaries of the first threshold valueand the first threshold value may be asymmetrical.

An embodiment consistent with the invention may be implemented within asystem for providing communication environment switchover. The system,for example, may include the first device and/or the second device.Either of the first device and/or the second device may include aprocessor in which the invention may be embodied. The processor maycomprise a memory storage and a processing unit coupled to the memorystorage. The processing unit may be operative to determine a receivedsignal strength level corresponding to a signal sent from the firstdevice and received at the second device. The received signal strengthlevel may be measured at the second device. In addition, the processingunit may be operative to cause the first device to be re-provisioned.For example, the processing unit may be operative to cause the firstdevice to be re-provisioned to communicate in a second environment ifthe first device is provisioned to communicate in a first environmentand if the received signal strength level is greater than a firstthreshold value. Furthermore, the processing unit may be operative tocause the first device to be re-provisioned to communicate in the firstenvironment if the first device is provisioned to communicate in thesecond environment and if the received signal strength level is lessthan a second threshold value. The second threshold value may be lessthan the first threshold value.

Consistent with an embodiment of the present invention, theaforementioned memory, processing unit, and other components may beimplemented within a system for providing communication environmentswitchover, such as system 100 as described above with respect toFIG. 1. Any suitable combination of hardware, software, and/or firmwaremay be used to implement the memory, processing unit, or othercomponents. By way of example, the memory, processing unit, or othercomponents may be implemented with any of the first device or the seconddevice, in combination with system 100. The aforementioned system andprocessors are exemplary and other systems and processors may comprisethe aforementioned memory, processing unit, or other components,consistent with embodiments of the present invention.

FIG. 3 shows a processor 300 that may be used in the first device (e.g.,DMH 105) or the second device (e.g., wireless access point 205) as shownin FIG. 1. As shown in FIG. 3, processor 300 may include a processingunit 325 and a memory 330. Memory 330 may include a software module 335and a database 340. While executing on processing unit 325 embodied ineither of the first device or the second device, software module 335 mayperform processes for providing communication environment switchover,including, for example, one or more of the stages of a method 400described below with respect to FIG. 4. Database 340 may be used, forexample, to temporarily store information while processor 300 executesone or more stages of method 400.

Processor 300 (“the processor”) may be implemented using a personalcomputer, network computer, mainframe, or other similarmicrocomputer-based workstation. The processor may though comprise anytype of computer operating environment, such as hand-held devices,multiprocessor systems, microprocessor-based or programmable senderelectronic devices, minicomputers, mainframe computers, and the like.The processor may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices.Furthermore, the processor may comprise a mobile terminal, such as asmart phone, a cellular telephone, a cellular telephone utilizingwireless application protocol (WAP), personal digital assistant (PDA),intelligent pager, portable computer, a hand held computer, aconventional telephone, a WiFi access point, or a facsimile machine. Theaforementioned systems and devices are exemplary and the processor maycomprise other systems or devices.

FIG. 4 is a flow chart setting forth the general stages involved in amethod 400 consistent with an embodiment of the invention for providingcommunication environment switchover. Method 400 may be implementedusing processor 300 as described above with respect to FIG. 3. Ways toimplement the stages of method 400 will be described in greater detailbelow. Method 400 begins at starting block 405 and proceeds to stage 410where processor 300 determines a received signal strength levelcorresponding to a signal sent from a first device (e.g., DMH 105) andreceived at a second device (e.g., wireless access point 205). Thereceived signal strength level may be measured at the second device.

For example, wireless access point 205 is equipped with a radiotransmitter and a receiver. DMH 105 is also equipped with a WiFi radiotransmitter and a receiver plus a GSM cellular radio transmitter andreceiver. In general, wireless access point 205 has more transmit powerand better receive sensitivity than DMH 105's radio transmitter andreceiver. Therefore, the ability of DMH 105 to operate effectively inconjunction with wireless access point 205 in supporting a VoIPapplication over WiFi is primarily determined by the strength of thesignal that wireless access point 205 is receiving from DMH 105.Although the mechanism for triggering roaming and in-call handover inDMH 105 between WiFiNoIP and GSM could be based on the received signalstrength that DMH 105 is receiving from wireless access point 205, VoIPover WiFi is a symmetrical application and the communication link fromwireless access point 205 to DMH 105 is much stronger than thecommunication link from DMH 105 to wireless access point 205, i.e., Inother words, the communication link between wireless access point 205and DMH 105 is asymmetric and the communication link from DMH 105 towireless access point 205 is the weak link.

From stage 410, where processor 300 determines the received signalstrength level, method 400 advances to decision block 420 whereprocessor 300 determines if the first device is provisioned tocommunicate in first environment 110 and if the received signal strengthlevel is greater than a first threshold value. For example, the firstthreshold value may comprise a value greater than or equal to −50 dBm.

If at decision block 420 processor 300 determined that the first deviceis provisioned to communicate in first environment 110 and that thereceived signal strength level is greater than the first thresholdvalue, method 400 advances to stage 430 where processor 300 causes thefirst device to be re-provisioned to communicate in second environment115. For example, when the user is outside of structure 120 with DMH 105operating in the GSM mode with an active call in progress and starts toenter structure 120 and WiFi radio coverage, DMH 105 will automaticallyassociate with wireless access point 205 and software in DMH 105 (e.g.,software module 335) and IMS 162 (e.g. using handover feature server165) will handover the call to WiFiNoIP and turn off the GSM radio. Thefirst stage in the handover process is for DMH 105 to associate withwireless access point 205 and complete session internet protocol (SIP)registration with the IMS Core Platform 162. After the association andSIP registration processes have been completed, it is important for DMH105 not to handover the call from GSM to WiFiNoIP until wireless accesspoint 205 is receiving sufficient signal strength from DMH 105 toestablish and maintain a VoIP call over WiFi. A process for triggeringin-call handover from GSM to WiFi/VoIP after successfully registeringwith wireless access point 205 is based on DMH 105 frequently querying(e.g., one query and response per second) wireless access point 205 via,for example, an 802.11k interface to obtain information from wirelessaccess point 205 concerning the received signal strength that the accesspoint is measuring from DMH 105. When the received signal strength thatwireless access point 205 is measuring from DMH 105 begins to exceed anacceptable received signal strength threshold (e.g., the firstthreshold) necessary to sustain the VoIP call over WiFi, then softwarein DMH 105 and handover feature server 165 (e.g. through IMS 162) willtrigger the in-call handover from the GSM to WiFiNoIP. For example,handover feature server 165 via third party call control may create athree-way-call by adding a WiFiNoIP leg from the DMH 105 for theexisting two-way call between the DMH 105 and an analog PSTN phone 180.The three-way call may consist of the GSM leg from the DMH 105, theWiFi/SIP leg from the DMH 105 and the analog leg from the analog PSTNphone 180. Once handover feature server 165 has both legs establishedfrom the DMH 105, handover feature server 165 may drop the GSM leg.

If at decision block 420 processor 300 determined, however, that thefirst device is not provisioned to communicate in first environment 110and that the received signal strength level is not greater than thefirst threshold value, method 400 advances to decision block 440 whereprocessor 300 determines if the first device is provisioned tocommunicate in second environment 115 and if the received signalstrength level less than the second threshold value. For example, thesecond threshold may comprise a value less than or equal to −70 dBm.

If at decision block 440 processor 300 determines that the first deviceis provisioned to communicate in the second environment and that thereceived signal strength level less than the second threshold value,method 400 advances to stage 450 where processor 300 causes the firstdevice to be re-provisioned to communicate in the first environment. Forexample, when the user is inside structure 120 with DMH 105 operating inthe WiFiNoIP mode with an active call and starts to leave WiFi radiocoverage, in order to maintain the continuity of the call it isimportant to trigger the handover of the call from WiFiNoIP to GSMbefore DMH 105 leaves WiFi coverage. A process for triggering in-callhandover is based on DMH 105 frequently querying (e.g., one query andresponse per second) wireless access point 205 via, for example, an802.11k interface to obtain information from wireless access point 205concerning the received signal strength that wireless access point 205is measuring from DMH 105. When the received signal strength thatwireless access point 205 is measuring from DMH 105 begins to fall belowan acceptable received signal strength threshold (e.g., the secondthreshold) necessary to sustain the VoIP call over WiFi, then softwarein DMH 105 (e.g., software module 335) will trigger the in-call handoverfrom WiFi/VoIP to GSM. For example, handover feature server 165 maycreate a three-way-call between DMH 105 and an analog PSTN phone 180,one leg of the tree-way-call on GSM and the other leg of thethree-way-call on WiFiNoIP. Once handover feature server 165 has bothlegs established, handover feature server 165 may drop the WiFiNoIP leg.

The mechanisms for executing the in-call handover from the WiFiNoIPenvironment to the GSM cellular environment have been defined in the3GPP IP Multimedia Subsystem (IMS) Voice Call Continuity (VCC) workingitem. This working item defines how an active call can be maintainedwhen DMH 105 moves from an IMS WiFi domain to a circuit switched GSMdomain. For example, WiFiNoIP to GSM in-call handover can only occurthen there is sufficient GSM received signal by DMH 105 to allow GSMregistration outside structure 120. Furthermore, DMH 105 may provide tothe user a audible and/or visual indication that the received signalstrength level is approaching the second threshold value. For example,when the user is inside structure 120 with DMH 105 operating in theWiFiNoIP mode with an active call and starts to leave WiFi radiocoverage, in order to maintain the continuity of the call it isimportant to trigger the handover of the call from WiFiNoIP to GSMbefore DMH 105 leaves WiFi coverage. Consequently, DMH 105 may provideto the user the audible and/or visual indication that the receivedsignal strength level is approaching the second threshold value. Inresponse to the indication, the user may wish to move to an area wherethe received signal strength level is stronger in order to stay in theWiFiNoIP mode.

If at decision block 440 processor 300 determined, however, that thefirst device is not provisioned to communicate in the second environmentand that the received signal strength level is not less than the secondthreshold value, or from stages 430 and 450, method 400 then ends atstage 460.

In another embodiment, first device 105, for example, can roam betweensecond environment 115 and the first environment 110 even when a call isnot active on DMH 105. When the user is outside structure 120 with DMH105 operating in the GSM mode without an active call and starts to enterstructure 120 and WiFi radio coverage, DMH 105 will automatically roamonto WiFi. Software in DMH 105 will turn off the GSM radio in DMH 105. Afirst stage in the roaming process is for DMH 105 to associate withwireless access point 205 and complete session internet protocol (SIP)registration with the IMS Core Platform 162. After the associationprocess and SIP registration have been completed, DMH 105 may not roamonto WiFiNoIP until wireless access point 205 is receiving sufficientsignal strength from DMH 105 to establish and maintain a VoIP call overWiFi. The process for triggering in-call handover after successfullyregistering with wireless access point 205 is based on DMH 105frequently querying (e.g., one query and response per second) wirelessaccess point 205 via an 802.11k interface to obtain information fromwireless access point 205 concerning the received signal strength thatwireless access point 205 is measuring from DMH 105. When the receivedsignal strength that wireless access point 205 is measuring from DMH 105begins to exceed an acceptable received signal strength threshold (i.e.,the first threshold) necessary to sustain the VoIP call over WiFi, thensoftware in DMH 105 will trigger the in-call handover from the GSM toWiFi.

When the user is inside structure 120 with DMH 105 operating in the WiFimode without an active call and starts to leave WiFi radio coverage, DMH105 will roam onto GSM. Software in DMH 105 will place the WiFi radio inDMH 105 into a sleep mode. The handover of the call may be triggeredfrom the WiFiNoIP environment to the GSM cellular environment before DMH105 leaves WiFi coverage. A process for triggering in-call handover isbased on DMH 105 regularly querying wireless access point 205 via an802.11k interface to obtain information from wireless access point 205concerning the received signal strength that wireless access point 205is measuring from DMH 105. When the received signal strength thatwireless access point 205 is measuring from DMH 105 begins to fall belowan acceptable received signal strength threshold (i.e., secondthreshold) necessary to sustain a VoIP call over WiFi, then software inDMH 105 will trigger the roaming from WiFi to GSM. In order for theroaming mechanism to work effectively as the user is walking out ofstructure 120 from WiFi to GSM, DMH 105 may frequently query wirelessaccess point 205, such as one query and response per second. It isunderstood that WiFi to GSM roaming can only occur when DMH 105 isreceiving adequate GSM received signal strength to allow GSMregistration.

Generally, consistent with embodiments of the invention, program modulesmay include routines, programs, components, data structures, and othertypes of structures that may perform particular tasks or that mayimplement particular abstract data types. Moreover, embodiments of theinvention may be practiced with other computer system configurations,including hand-held devices, multiprocessor systems,microprocessor-based or programmable consumer electronics,minicomputers, mainframe computers, and the like. Embodiments of theinvention may also be practiced in distributed computing environmentswhere tasks are performed by remote processing devices that are linkedthrough a communications network. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

Furthermore, embodiments of the invention may be practiced in anelectrical circuit comprising discrete electronic elements, packaged orintegrated electronic chips containing logic gates, a circuit utilizinga microprocessor, or on a single chip containing electronic elements ormicroprocessors. Embodiments of the invention may also be practicedusing other technologies capable of performing logical operations suchas, for example, AND, OR, and NOT, including but not limited tomechanical, optical, fluidic, and quantum technologies. In addition,embodiments of the invention may be practiced within a general purposecomputer or in any other circuits or systems.

Embodiments of the invention, for example, may be implemented as acomputer process (method), a computing system, or as an article ofmanufacture, such as a computer program product or computer readablemedia. The computer program product may be a computer storage mediareadable by a computer system and encoding a computer program ofinstructions for executing a computer process. The computer programproduct may also be a propagated signal on a carrier readable by acomputing system and encoding a computer program of instructions forexecuting a computer process. Accordingly, the present invention may beembodied in hardware and/or in software (including firmware, residentsoftware, micro-code, etc.). In other words, embodiments of the presentinvention may take the form of a computer program product on acomputer-usable or computer-readable storage medium havingcomputer-usable or computer-readable program code embodied in the mediumfor use by or in connection with an instruction execution system. Acomputer-usable or computer-readable medium may be any medium that cancontain, store, communicate, propagate, or transport the program for useby or in connection with the instruction execution system, apparatus, ordevice.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. More specific computer-readable medium examples (anon-exhaustive list), the computer-readable medium may include thefollowing: an electrical connection having one or more wires, a portablecomputer diskette, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, and a portable compact disc read-only memory(CD-ROM). Note that the computer-usable or computer-readable mediumcould even be paper or another suitable medium upon which the program isprinted, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, or otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

Embodiments of the present invention, for example, are described abovewith reference to block diagrams and/or operational illustrations ofmethods, systems, and computer program products according to embodimentsof the invention. The functions/acts noted in the blocks may occur outof the order as show in any flowchart. For example, two blocks shown insuccession may in fact be executed substantially concurrently or theblocks may sometimes be executed in the reverse order, depending uponthe functionality/acts involved.

While certain embodiments of the invention have been described, otherembodiments may exist. Furthermore, although embodiments of the presentinvention have been described as being associated with data stored inmemory and other storage mediums, data can also be stored on or readfrom other types of computer-readable media, such as secondary storagedevices, like hard disks, floppy disks, or a CD-ROM, a carrier wave fromthe Internet, or other forms of RAM or ROM. Further, the disclosedmethods' stages may be modified in any manner, including by reorderingstages and/or inserting or deleting stages, without departing from theinvention.

While the specification includes examples, the invention's scope isindicated by the following claims. Furthermore, while the specificationhas been described in language specific to structural features and/ormethodological acts, the claims are not limited to the features or actsdescribed above. Rather, the specific features and acts described aboveare disclosed as example for embodiments of the invention.

1. A device, comprising: a memory that retains program modules; and aprocessing unit that executes one or more of the program modules toperform the following: determine a signal strength level of atransmitted signal based on one or more queries of a measured strengthlevel at a wireless access point; and cause switchover of the deviceamongst a first communication environment and a second communicationenvironment.
 2. The device of claim 1, wherein, to cause the switchoverof the device amongst the first communication environment and the secondcommunication environment, the processing unit executes one or more ofthe program modules to further perform the following: determine if thedevice is provisioned to communicate in the first communicationenvironment; and if the device is provisioned to communicate in thefirst communication environment and the signal strength level is greaterthan a first threshold, cause the device to be re-provisioned tocommunicate in the second communication environment.
 3. The device ofclaim 2, if the device is not provisioned to communicate in the firstcommunication environment and the signal strength level is not greaterthat the first threshold, the processing unit executes one or more ofthe program modules to further perform the following: determine if thedevice is provisioned to communicate in the second communicationenvironment; determine if the signal strength level is less than asecond threshold, wherein the second threshold is lower than the firstthreshold; and if the device is provisioned to communicate in the secondcommunication environment and the signal strength level is less than thesecond threshold, cause the device to be re-provisioned to communicatein the first communication environment.
 4. The device of claim 1,wherein the first communication environment comprises a cellularwireless network over licensed spectrum comprising wirelesscommunication frequencies assigned to a service provider.
 5. The deviceof claim 2, wherein the second communication environment comprises apacketized data network configured to provide wireless service overunlicensed spectrum comprising at least one frequency not assigned to aservice provider, wherein the packetized data network comprises awireless fidelity/voice-over-internet-protocol (WiFiNoIP) network. 6.The device of claim 1, wherein the switchover is in-call handover andthe processing unit executes the one or more of the program modules tocause the device to be re-provisioned to communicate in the secondcommunication environment during an active call.
 7. The device of claim3, wherein the processing unit executes one or more of the programmodules to provide at least one of an audible indication or a visualindication that the signal strength level is approaching the secondthreshold value.
 8. The device of claim 2, wherein the first thresholdcomprises a value less than or equal to −70 dBm.
 9. The device of claim3, wherein the second threshold comprises a values less than or equal to−50 dBm.
 10. The device of claim 1, wherein the device is a dual modehandset and the wireless access point is a WiFi access point.
 11. Amethod, comprising: employing at least a computer processor to executecode instructions retained in a computer-readable medium, the executedcode instructions implement the following acts: determining a strengthlevel of signal that is transmitted by a device by frequently querying awireless access point to obtain information on a measurement of strengthof the transmitted signal that is received at the wireless access point;and triggering switchover of the device amongst a first environment anda second environment based in part on at least one of the strength leveland provisioning of the device.
 12. The method of claim 11, thetriggering act comprising: if the device is provisioned to communicatein the first environment and the signal strength level is greater than afirst threshold, causing the device to be re-provisioned to communicatein a second environment; and if the device is not provisioned tocommunicate in the first environment and the signal strength level isnot greater that the first threshold: determining if the device isprovisioned to communicate in the second environment and determining ifthe signal strength level is less than a second threshold, wherein thesecond threshold is lower than the first threshold; and if the device isprovisioned to communicate in the second environment and the signalstrength level is less than the second threshold, causing the device tobe re-provisioned to communicate in the first environment.
 13. Themethod of claim 12, wherein the first environment comprises a cellularwireless network over licensed spectrum comprising wirelesscommunication frequencies assigned to a service provider.
 14. The methodof claim 13, wherein the second environment comprises a packetized datanetwork configured to provide wireless service over unlicensed spectrumcomprising at least one frequency not assigned to a service provider.15. The method of claim 12, wherein the first threshold comprises avalue less than or equal to −70 dBm.
 16. The method of claim 12, whereinthe second threshold comprises a values less than or equal to −50 dBm.17. The method of claim 11, wherein switchover is one of in-callhandover or roaming.
 18. A system, comprising: means for determining astrength level of a signal that is transmitted by a first device andreceived by a second device, the first device comprising a dual modehandset (DMH) and the second device comprising a wireless access point;and means for triggering in-call handover of the first device amongst afirst environment and a second environment based in part on at least oneof the strength level and provisioning of the first device.
 19. Thesystem of claim 18, wherein means for triggering in-call handoverincludes: if the first device is provisioned to communicate in the firstenvironment and the strength level of the signal is greater than a firstthreshold, means for causing the device to be re-provisioned tocommunicate in a second environment; and if the first device is notprovisioned to communicate in the first environment and the strengthlevel of the signal is not greater that the first threshold: means fordetermining if the first device is provisioned to communicate in thesecond environment and means determining if the strength level of thesignal is less than a second threshold, wherein the second threshold islower than the first threshold; and if the first device is provisionedto communicate in the second environment and the strength level of thesignal is less than the second threshold, means for causing the firstdevice to be re-provisioned to communicate in the first environment. 20.The system of claim 18, wherein means for determining the strength ofthe signal comprises means for querying the second device to obtaininformation on a measurement of strength level of the signal that isreceived at the second device.